This invention relates to knocking detectors for internal combustion engines.
Conventional knocking detectors for internal combustion engines employ an acceleration sensor mounted adjacent to a cylinder of the engines, and subject an electric signal outputted from the acceleration sensor to frequency analysis to judge whether or not knocking has taken place, whose occurrence depends on running conditions of an automobile, etc.
The conventional knocking detectors for the internal combustion engines, constructed as described above, base knocking judgment on the output level of the acceleration sensor mounted on the engines. Therefore, noise (e.g., valve noise) other than knocking is also picked up by the acceleration sensor, which has made it necessary to put both knocking and other noise to frequency analysis for knocking judgment.